EP1336665B1 - Cold reduced enamelling steel sheet and an enamelled structure comprising a component of such a steel sheet - Google Patents
Cold reduced enamelling steel sheet and an enamelled structure comprising a component of such a steel sheet Download PDFInfo
- Publication number
- EP1336665B1 EP1336665B1 EP20020075654 EP02075654A EP1336665B1 EP 1336665 B1 EP1336665 B1 EP 1336665B1 EP 20020075654 EP20020075654 EP 20020075654 EP 02075654 A EP02075654 A EP 02075654A EP 1336665 B1 EP1336665 B1 EP 1336665B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- steel sheet
- sheet according
- max
- ppm
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
- C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
- C21D8/0436—Cold rolling
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
Definitions
- the invention relates to cold reduced enamelling steel sheet.
- Cold reduced enamelling steel sheet is frequently used to fabricate products such as domestic appliances. During fabrication of such products, the steel sheet material is usually coated with an enamel layer. It is then desirable to obtain an enamel layer with good adhesion to the steel sheet, and with at most only a few visible defects such as fish scale patterns. It is known that the resistance to fish scale formation can be improved by a synergistic effect of boron and nitrogen content in cold reduced steel sheet.
- JP-A 2 030 738 relates to a steel plate for enamelling having excellent press formability and fish scale resistance as well as high adhesion at the time of direct one-shot enamelling. Its composition comprises Se 0.002-0.02 wt%, 0.010-0.10%REM and Ti.
- the cold reduced enamelling steel sheet according to the invention comprises (in weight-ppm unless otherwise indicated)
- an enamelling steel sheet with a minimum of alloying elements that has deep drawing properties which are sufficiently good. After applying and firing white enamel, the steel sheet is essentially free from fish scale defects, and the enamel adhesion is satisfactory.
- the combination of B and N enables formation of precipitates that help suppress the formation of fish scales.
- the atomic ratio B/N should be more than 0.80. It is now found that the mechanical properties, in particular deep drawing properties, are better if the amount of excess B above the atomic ratio B/N of 1.00 is limited to at most 144/6 ppm (i.e. 24 ppm) by weight. Thus, when the B-content exceeds B max , the mechanical properties are unnecessarily deteriorating. This deterioration is currently thought to be related to the presence of acid soluble B and/or free B in the steel matrix.
- oxygen is not added to extra amounts, since it might form unnecessary precipitates that are unfavourable for the mechanical properties for deep drawing, such as increase in yield strength and lowering of the elongation.
- Oxygen is be present in the steel sheet after oxygen steel making process typically up to an amount of 35 weight-ppm.
- the amount of acid soluble Al should be limited to at most 300 weight-ppm. Deep drawing properties may improve as the amount of Al as is kept low as possible, preferably lower than 150 weight-ppm.
- the total amount of Al that may be present in the steel depends primarily on the oxygen content. The total amount of Al is preferably sufficiently high to bind essentially all the oxygen that is present in the steel sheet.
- Mn is important for forming MnS precipitates, and MnO precipitates in the case that not all oxygen is already bound by Al. S may be, and in practice often is present in the steel sheet as unintentional element. A significant effect is obtained when at least 0.10 wt. % of Mn is present in the steel sheet. Preferably, the amount of Mn is at least 0.23 wt. % to gain full advantage of this alloying element. However, for maintaining sufficient deep drawing capability of the steel sheet, the Mn content should be kept to a maximum of 0.50 wt. %.
- the steel sheet also contains:
- an atomic ratio Cu/P of between 1.00 and 1.50 is preferred, since under this condition in most cases the pickling behaviour is sufficiently good, with less Cu added to the alloy.
- the steel sheet also contains Si ⁇ 190 weight-ppm.
- Addition of Si to amounts above 190 weight-ppm have an effect in increasing the yield strength and lowering the elongation of the resulting cold rolled steel sheet, which is in general a deterioration of the deep drawability.
- some amount of excess B above the atomic ratio B/N of 1.00 can be tolerated.
- the amount of excess B above the atomic ratio B/N of 1.00 is limited to at most 83/6 ppm by weight.
- the mechanical properties are particularly optimised for relatively high Si content, i.e. in the range of 40 weight-ppm to 190 wt.-ppm.
- the recrystallisation temperature is also lower in that case.
- the deterioration of the mechanical deep drawing properties with the excess B above the atomic ratio B/N of 1.00 in this is limit is currently thought to be related to the presence of acid soluble B.
- B min N ⁇ 0.90 ⁇ 10.8/14.
- B/N the atomic ratio
- B min N ⁇ 1.00 ⁇ 10.8/14.
- the atomic ratio B/N is higher than 1.00. It has been found that a small excess of B can be tolerated regarding the mechanical properties, with the advantage that it ensures that all N is indeed precipitated. Herewith the formation of fish scales is essentially fully suppressed.
- the steel sheet comprises: 45 ⁇ N ⁇ 110.
- the formation of fish scale defects has been found to be suppressed better if the amount of N present in the steel sheet is at least 45 weight-ppm.
- the steel sheet comprises less than 89 weight-ppm N. It has been found that the amount of added B can then be reduced while the formation of fish scale defects is nevertheless sufficiently reduced.
- the steel sheet comprises less than 89 weight-ppm N
- B max N ⁇ 1.35 ⁇ 10.8/14.
- the steel sheet comprises less than 89 weight-ppm N
- B max N ⁇ 1.20 ⁇ 10.8/14.
- Si is not deliberately added during the steel making process, and only present as an unintentional and/or inevitable impurity, for instance, at a level of approximately 10 weight-ppm. It is found that with such low Si content, a relatively high excess B can be tolerated without noticeable deterioration of the elongation.
- the maximum amount of C in the steel sheet is 50 ppm by weight.
- the maximum amount of C is 40 weight-ppm.
- the amount of C in the steel sheet is lower than 30 weight-ppm by weight.
- the strengthening of the steel sheet by ageing is maximised.
- the cold reduced enamelling steel sheet has a composition of C, Mn, Al, S, N, B, Cu, P in the amounts as specified above, the balance being Fe and unintentional and/or inevitable impurities such as O, Si.
- the steel sheet as described above has a grain size according to ASTM of 9.5 units or less.
- ASTM ASTM of 9.5 units or less.
- the yield strength is between 140 MPa and 190 MPa
- the tensile strength is between 270 MPa and 350 MPa
- the elongation to fracture is at least 35 %, all numbers measured in cross sectional direction to rolling in annealed, unaged and 1% temper rolled condition.
- the steel sheet can have an r -value (at 90° to rolling direction) of higher than 1.85, and/or an n-value exceeding 0.233.
- the invention is applicable to an enamelled structure comprising at least one component made of the above described steel sheet, provided with an enamel layer.
- Cold reduced enamelling steel sheet can be produced by preparing a suitable steel melt and casting the melt into a slab.
- the production process can include operations of hot rolling the slab, pickling the rolled product, cold rolling, annealing, temper rolling.
- cold rolling can be applied to a reduction exceeding 50 %, or exceeding 70 %, and in an embodiment not exceeding 90 %.
- annealing can be performed to a temperature between the recrystallisation temperature of the rolled sheet and the Ar 3 temperature. Annealing may be performed as coil annealing, continuous annealing, or any suitable type of annealing.
- temper rolling may be performed to a reduction between 0.5 % and 2 %.
- the embodiments of the invention are, however, not limited to these operations and conditions.
- the melts were cast and hot rolled, with a finishing temperature of 930 °C. Then the sheets were cooled at a velocity of 20°C/s, and coiled at a temperature of 690 °C.
- the sheets were pickled at a temperature of 70 °C, and cold rolled to three reductions of 75 %, 80 %, and 85 % (corresponding to respective final thicknesses of 1.0 mm, 0.8 mm, and 0.6 mm) for each type.
- the recrystallisation temperature for tight coil annealing was determined for each type for various reductions using a heating rate of 2.4 ⁇ 10 -5 /sec in HN x . Each sample was heated to a certain temperature, and cooled, and successively heated to a temperature 10° above the previous temperature. After each cooling step, a microscopic study of the microstructure of the sample was performed to determine whether recrystallisation had occurred.
- the thus found recrystallisation temperatures are given in °C in the following Table II.
- each type of thus obtained and rolled steel sheet was tight-coil annealed at 640 °C using a heating rate of 2.4 ⁇ 10 -5 /sec, and after cooling down to room temperature subsequently temper rolled to a 1 % reduction.
- White enamel was applied to these steel sheets, using various firing temperatures between 780 and 860°C.
- the reference steel sheet showed a high abundance of fish scales after application of white enamel, while none of the steel sheets of types 1 or 2 suffered from visible fish scale defects. This shows that in cold rolled sheet even a low B content of 64 weight-ppm can be sufficient to suppress fish scale formation, as long as the amount of B is carefully adapted to the amount of N that is present in the steel sheet. Also, the adhesion of the white enamel was excellent.
- Table IV shows results of mechanical tests of temper rolled (1 %) non-aged sheet sheets. The results are average results obtained on 75, 80, and 85 % cold reduced sheets, measured in the transverse direction, according to the small Euronorm using a small rod from the sheet.
- R p denotes yield strength
- R m is the tensile strength
- a g is the uniform elongation
- A80 the elongation to fracture.
- transverse r -value 90°
- n -value (90°) and n -value.
- Both types 1 and 2 being embodiments of the invention have better mechanical properties than the reference steel sheet, particularly in terms of elongation and r -value.
- the elongation percentages of steel type 1 slightly exceed those of type 2.
- Type 1 contains more Al as than type 2, yet type 1 has slightly better mechanical properties. The present understanding is that this shows the onset of the adverse effect of excess B, since in type 2 both the absolute amount of B as well as the atomic ratio B/N are higher than those of type 1.
- Embodiment of the enamelling steel sheet according to the invention have also been prepared in a production plant.
- the spectroscopically analysed compositions are given in Table V.
- the cast melts were hot rolled, and cold rolled to a cold reduction of 80 % and a final thickness of 0.9 mm.
- the recrystallisation temperatures of these steel sheets were determined to be 650 °C, using the same method as described above. This is slightly higher than in the laboratory melts.
- the cold rolled steel sheets were tight coil annealed to a temperature of 650°C, and subsequently cooled down to room temperature and temper rolled by 0.8 %.
- the grain size in cross section to rolling direction was determined to be 9.0 ASTM units for both types 3 and 4, using the ASTM standard.
- the resistance against fish scale formation is in both types 3 and 4 as good as the laboratory melts, and the adhesion of enamel is good.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Description
- The invention relates to cold reduced enamelling steel sheet.
- Cold reduced enamelling steel sheet is frequently used to fabricate products such as domestic appliances. During fabrication of such products, the steel sheet material is usually coated with an enamel layer. It is then desirable to obtain an enamel layer with good adhesion to the steel sheet, and with at most only a few visible defects such as fish scale patterns. It is known that the resistance to fish scale formation can be improved by a synergistic effect of boron and nitrogen content in cold reduced steel sheet.
-
JP-A 2 030 738 - It is an object of the present invention to provide an alternative enamelling steel sheet. It is another object of the invention to provide a cheap enamelling steel sheet that is suitable for white enamel. It is another object of the invention to provide an enamelling steel sheet with improved balance in enamelling behaviour and mechanical properties, in particular elongation.
- The cold reduced enamelling steel sheet according to the invention comprises (in weight-ppm unless otherwise indicated)
- 5 ≤ C ≤ 90;
- 0.10 ≤ Mn ≤ 0.50 (wt. %);
- Alas ≤ 300 (acid soluble Al);
- O ≤ 35;
- 30 ≤ N ≤ 110;
- Bmin ≤ B ≤ Bmax;
wherein Bmin = N×0.80×10.8/14 and Bmax = N×10.8/14 + 144/6;- 50 ≤ P ≤ 160; in combination with
- Cumin ≤ Cu ≤ Cumax;
and optionally- Si < 190;
- Herewith is provided an enamelling steel sheet with a minimum of alloying elements, that has deep drawing properties which are sufficiently good. After applying and firing white enamel, the steel sheet is essentially free from fish scale defects, and the enamel adhesion is satisfactory.
- The combination of B and N enables formation of precipitates that help suppress the formation of fish scales. In order to sufficiently suppress the formation of fish scale defects, the atomic ratio B/N should be more than 0.80. It is now found that the mechanical properties, in particular deep drawing properties, are better if the amount of excess B above the atomic ratio B/N of 1.00 is limited to at most 144/6 ppm (i.e. 24 ppm) by weight. Thus, when the B-content exceeds Bmax, the mechanical properties are unnecessarily deteriorating. This deterioration is currently thought to be related to the presence of acid soluble B and/or free B in the steel matrix.
- In an embodiment, oxygen is not added to extra amounts, since it might form unnecessary precipitates that are unfavourable for the mechanical properties for deep drawing, such as increase in yield strength and lowering of the elongation.
- Oxygen is be present in the steel sheet after oxygen steel making process typically up to an amount of 35 weight-ppm.
- The amount of acid soluble Al (Alas) should be limited to at most 300 weight-ppm. Deep drawing properties may improve as the amount of Alas is kept low as possible, preferably lower than 150 weight-ppm. The total amount of Al that may be present in the steel depends primarily on the oxygen content. The total amount of Al is preferably sufficiently high to bind essentially all the oxygen that is present in the steel sheet.
- Mn is important for forming MnS precipitates, and MnO precipitates in the case that not all oxygen is already bound by Al. S may be, and in practice often is present in the steel sheet as unintentional element. A significant effect is obtained when at least 0.10 wt. % of Mn is present in the steel sheet. Preferably, the amount of Mn is at least 0.23 wt. % to gain full advantage of this alloying element. However, for maintaining sufficient deep drawing capability of the steel sheet, the Mn content should be kept to a maximum of 0.50 wt. %.
- The steel sheet also contains:
- 50 ≤ P ≤ 160; in combination with
- However, an atomic ratio Cu/P of between 1.00 and 1.50 is preferred, since under this condition in most cases the pickling behaviour is sufficiently good, with less Cu added to the alloy.
- Optionally the steel sheet also contains Si ≤ 190 weight-ppm. Addition of Si to amounts above 190 weight-ppm have an effect in increasing the yield strength and lowering the elongation of the resulting cold rolled steel sheet, which is in general a deterioration of the deep drawability. Thus by limiting the amount of Si to a maximum of 190 weight-ppm, some amount of excess B above the atomic ratio B/N of 1.00 can be tolerated.
- Preferably the amount of excess B above the atomic ratio B/N of 1.00 is limited to at most 83/6 ppm by weight. Herewith the mechanical properties are particularly optimised for relatively high Si content, i.e. in the range of 40 weight-ppm to 190 wt.-ppm. The recrystallisation temperature is also lower in that case. The deterioration of the mechanical deep drawing properties with the excess B above the atomic ratio B/N of 1.00 in this is limit is currently thought to be related to the presence of acid soluble B.
- It is preferred that Bmin = N×0.90×10.8/14. Herewith the atomic ratio B/N is higher than 0.90. Herewith it is better assured that all nitrogen is indeed precipitated with B.
- It is more preferred that Bmin = N×1.00×10.8/14. Herewith the atomic ratio B/N is higher than 1.00. It has been found that a small excess of B can be tolerated regarding the mechanical properties, with the advantage that it ensures that all N is indeed precipitated. Herewith the formation of fish scales is essentially fully suppressed.
- In an embodiment, the steel sheet comprises:
45 ≤ N ≤ 110. The formation of fish scale defects has been found to be suppressed better if the amount of N present in the steel sheet is at least 45 weight-ppm. - In an embodiment, the steel sheet comprises less than 89 weight-ppm N. It has been found that the amount of added B can then be reduced while the formation of fish scale defects is nevertheless sufficiently reduced.
- In an embodiment wherein the steel sheet comprises less than 89 weight-ppm N, it is preferred that Bmax = N×1.35×10.8/14. By keeping the atomic ratio B/N smaller than or equal to 1.35, the mechanical properties are kept closer to their optimum, than by simply limiting the amount of excess B above the atomic ratio B/N of 1.00 to 144/6 ppm by weight.
- In an embodiment wherein the steel sheet comprises less than 89 weight-ppm N, it is preferred that Bmax = N×1.20×10.8/14. By keeping the atomic ratio B/N smaller than or equal to 1.20, the mechanical properties are kept close to their optimum. It is more preferred to keep the atomic ratio B/N smaller than or equal to 1.10. Herewith it is even better assured that no deteriorating effect on the mechanical properties results from the B addition.
- When the amount of Si is below 40 weight-ppm, the elongation and thus the deep drawability, of the cold rolled steel sheet is significantly higher than for amounts of 40 weight-ppm and above.
- Preferably, Si is not deliberately added during the steel making process, and only present as an unintentional and/or inevitable impurity, for instance, at a level of approximately 10 weight-ppm. It is found that with such low Si content, a relatively high excess B can be tolerated without noticeable deterioration of the elongation.
- In a preferred embodiment, the maximum amount of C in the steel sheet is 50 ppm by weight. Herewith the ageing properties are better suited. In a more preferred embodiment, the maximum amount of C is 40 weight-ppm. In a yet more preferred embodiment, the amount of C in the steel sheet is lower than 30 weight-ppm by weight. Herewith, the strengthening of the steel sheet by ageing is maximised.
- In an embodiment of the invention the cold reduced enamelling steel sheet has a composition of C, Mn, Al, S, N, B, Cu, P in the amounts as specified above, the balance being Fe and unintentional and/or inevitable impurities such as O, Si.
- In an embodiment of the invention, the steel sheet as described above has a grain size according to ASTM of 9.5 units or less. Herewith the desired mechanical properties and the pickling properties are achieved.
- In an embodiment, the yield strength is between 140 MPa and 190 MPa, the tensile strength is between 270 MPa and 350 MPa, and the elongation to fracture is at least 35 %, all numbers measured in cross sectional direction to rolling in annealed, unaged and 1% temper rolled condition. With these mechanical properties, the enamelling steel is sufficiently suited for most deep drawing applications. The steel sheet can have an r-value (at 90° to rolling direction) of higher than 1.85, and/or an n-value exceeding 0.233.
- The invention is applicable to an enamelled structure comprising at least one component made of the above described steel sheet, provided with an enamel layer.
- Cold reduced enamelling steel sheet can be produced by preparing a suitable steel melt and casting the melt into a slab. The production process can include operations of hot rolling the slab, pickling the rolled product, cold rolling, annealing, temper rolling. In particular, cold rolling can be applied to a reduction exceeding 50 %, or exceeding 70 %, and in an embodiment not exceeding 90 %. In particular, annealing can be performed to a temperature between the recrystallisation temperature of the rolled sheet and the Ar3 temperature. Annealing may be performed as coil annealing, continuous annealing, or any suitable type of annealing. In particular, temper rolling may be performed to a reduction between 0.5 % and 2 %. The embodiments of the invention are, however, not limited to these operations and conditions.
- The invention will be explained according to some embodiments of the invention.
- Laboratory melts were provided with various compositions as determined using spectrometric analysis and shown in Table I, in wt. ppm except for Mn in which case wt. % is used.
Table I Type C Mn O Al Alas B N B/N Si Cu P S Ref. 35 0.44 19 180 150 0 32 0 70 220 70 350 1 26 0.45 20 140 100 64 92 0.90 80 230 70 80 2 26 0.42 33 40 0 73 83 1.14 40 260 70 90
For reference, the atomic ratio B/N is also included in Table I. - B was added to the melt in the form of FeB after Al and Mn had been added. The composition of the melts were determined using spectrometric analysis of the melts. The amount of C in these steel types (between 20 and 30 weight-ppm) can be achieved in most oxygen blowing steel making factories.
- The melts were cast and hot rolled, with a finishing temperature of 930 °C. Then the sheets were cooled at a velocity of 20°C/s, and coiled at a temperature of 690 °C.
- After coil cooling, the sheets were pickled at a temperature of 70 °C, and cold rolled to three reductions of 75 %, 80 %, and 85 % (corresponding to respective final thicknesses of 1.0 mm, 0.8 mm, and 0.6 mm) for each type.
- The recrystallisation temperature for tight coil annealing was determined for each type for various reductions using a heating rate of 2.4× 10-5 /sec in HNx. Each sample was heated to a certain temperature, and cooled, and successively heated to a temperature 10° above the previous temperature. After each cooling step, a microscopic study of the microstructure of the sample was performed to determine whether recrystallisation had occurred. The thus found recrystallisation temperatures are given in °C in the following Table II.
Table II Type Cold reduced by: 75% 80 % 85% Ref. 640 640 640 1 640 640 640 2 610 620 620 - After cold reduction, each type of thus obtained and rolled steel sheet was tight-coil annealed at 640 °C using a heating rate of 2.4×10-5 /sec, and after cooling down to room temperature subsequently temper rolled to a 1 % reduction.
- The final grain structure in cross section of the rolling direction was determined after cold rolling, annealing, and temper rolling to a 1 % reduction according to the ASTM standard. The results are given in the following Table III in ASTM units.
Table III Type Cold reduced by 75 % 80 % 85 % Ref. 9.5 9.5 10 1 9.0 9.5 9.5 2 9.0 9.0 9.0 - White enamel was applied to these steel sheets, using various firing temperatures between 780 and 860°C. The reference steel sheet showed a high abundance of fish scales after application of white enamel, while none of the steel sheets of types 1 or 2 suffered from visible fish scale defects. This shows that in cold rolled sheet even a low B content of 64 weight-ppm can be sufficient to suppress fish scale formation, as long as the amount of B is carefully adapted to the amount of N that is present in the steel sheet. Also, the adhesion of the white enamel was excellent.
- The following Table IV shows results of mechanical tests of temper rolled (1 %) non-aged sheet sheets. The results are average results obtained on 75, 80, and 85 % cold reduced sheets, measured in the transverse direction, according to the small Euronorm using a small rod from the sheet. R p denotes yield strength, R m is the tensile strength, Ag is the uniform elongation, and A80 the elongation to fracture. Also given are transverse r-value (90°) and n-value.
Table IV Type R p MPa R m MPa A g % A80 % r n Ref. 195 320 22 31 1.48 0.214 1 162 301 26 38 1.94 0.241 2 160 296 26 37 2.07 0.243 - Embodiment of the enamelling steel sheet according to the invention have also been prepared in a production plant. The spectroscopically analysed compositions are given in Table V.
Table V Type C Mn O Al Alas B N B/N Si Cu P S 3 50 0.29 20 260 230 59 60 1.27 10 250 100 130 4 20 0.30 25 240 200 65 64 1.32 10 250 100 140 - The cold rolled steel sheets were tight coil annealed to a temperature of 650°C, and subsequently cooled down to room temperature and temper rolled by 0.8 %. The grain size in cross section to rolling direction was determined to be 9.0 ASTM units for both types 3 and 4, using the ASTM standard.
- The mechanical properties of these steel sheets were determined in cross section to the rolling direction as was done with the laboratory melts above. The results are shown in Table VI.
Table VI R p R m A g A80 r n Type MPa MPa % % 3 162 297 24 45 1.97 0.220 4 168 302 23 45 1.92 0.215 - The resistance against fish scale formation is in both types 3 and 4 as good as the laboratory melts, and the adhesion of enamel is good.
Claims (14)
- Cold reduced enamelling steel sheet comprising (in weight ppm unless otherwise indicated)5 ≤ C ≤ 90;0.10 ≤ Mn ≤ 0.50 (wt. %);Alas ≤ 300 (acid soluble Al);O ≤ 35;S ≤ 350;30 ≤ N ≤ 110;Bmin < B ≤ Bmax;wherein Bmin = N×0.80×10.8/14 and Bmax = N×10.8/14 + 144/6;50 ≤ P ≤ 160; in combination withCumin ≤ Cu ≤ Cumax;wherein Cumin = P×1.00×63.6/31 and Cumax = P×2.00×63.6/31and optionallyin each case the balance being Fe and unintentional and/or inevitable impurities.Si ≤190;
- Steel sheet according to claim 1, wherein Bmax = N×10.8/14 + 83/6.
- Steel sheet according to claim 1 or 2, wherein Bmin = N×0.90×10.8/14.
- Steel sheet according to claim 1, 2, or 3, wherein Bmin = N×1.00×10.8/14.
- Steel sheet according to any one of the preceding claims, wherein
45 ≤ N ≤ 110. - Steel sheet according to any one of the preceding claims, wherein
30 ≤ N < 89. - Steel sheet according to claim 6, wherein Bmax=N×1.35×10.8/14.
- Steel sheet according to claim 6, wherein Bmax = N×1.20×10.8/14.
- Steel sheet according to any one of the preceding claims, wherein Si < 40.
- Steel sheet according to any one of the preceding claims, wherein Si is present as an unintentional and/or inevitable impurity.
- Steel sheet according to any one of the claims 1 to 10, wherein Cumax = P×1.50×63.6/31.
- Steel sheet according to any one of the claims 1 to 11, wherein the maximum amount of C is 30 ppm by weight.
- Steel sheet according to any one of the preceding claims, wherein the grain size according to ASTM is 9.5 units or less.
- Steel sheet according to any one of the preceding claims, wherein the yield strength is between 140 MPa and 190 MPa, the tensile strength is between 270 MPa and 350 MPa, and the elongation to fracture is at least 35 %.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP20020075654 EP1336665B1 (en) | 2002-02-18 | 2002-02-18 | Cold reduced enamelling steel sheet and an enamelled structure comprising a component of such a steel sheet |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP20020075654 EP1336665B1 (en) | 2002-02-18 | 2002-02-18 | Cold reduced enamelling steel sheet and an enamelled structure comprising a component of such a steel sheet |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1336665A1 EP1336665A1 (en) | 2003-08-20 |
EP1336665B1 true EP1336665B1 (en) | 2008-07-02 |
Family
ID=27619170
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP20020075654 Expired - Lifetime EP1336665B1 (en) | 2002-02-18 | 2002-02-18 | Cold reduced enamelling steel sheet and an enamelled structure comprising a component of such a steel sheet |
Country Status (1)
Country | Link |
---|---|
EP (1) | EP1336665B1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014170315A1 (en) | 2013-04-15 | 2014-10-23 | Tata Steel Ijmuiden B.V. | Cold reduced enamelling steel sheet, method for its production, and use of such steel |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57104627A (en) * | 1980-12-19 | 1982-06-29 | Nippon Kokan Kk <Nkk> | Manufacture of cold rolled soft steel plate with superior press formability by continuous annealing |
JPS6045689B2 (en) * | 1982-02-19 | 1985-10-11 | 川崎製鉄株式会社 | Method for manufacturing cold rolled steel sheet with excellent press formability |
JPH0759735B2 (en) * | 1988-07-20 | 1995-06-28 | 川崎製鉄株式会社 | Steel sheet for direct enamel with excellent bubble resistance and black spot defects |
KR100221349B1 (en) * | 1994-02-17 | 1999-09-15 | 에모또 간지 | Method of manufacturing canning steel sheet with non-aging property and workability |
JP3067569B2 (en) * | 1995-01-25 | 2000-07-17 | 日本鋼管株式会社 | Enamelled steel with excellent nail skipping resistance, black spot resistance and aging resistance |
KR970703439A (en) * | 1995-03-27 | 1997-07-03 | 다나까 미노루 | ULTRALOW-CARBON COLD-ROLLED SHEET AND GALVANIZED SHEET BOTH EXCELLENT IN FATIGUE CHARACTERISTICS AND PROCESS FOR PRODUCING BOTH |
JP3293424B2 (en) * | 1995-09-25 | 2002-06-17 | 日本鋼管株式会社 | Manufacturing method of non-age steel non-aging ultra low carbon cold rolled steel sheet |
JP3377155B2 (en) * | 1996-02-26 | 2003-02-17 | 日本鋼管株式会社 | Manufacturing method of steel sheet for extremely low carbon cans |
-
2002
- 2002-02-18 EP EP20020075654 patent/EP1336665B1/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
EP1336665A1 (en) | 2003-08-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2554699B1 (en) | Steel sheet with high tensile strength and superior ductility and method for producing same | |
EP3400316B1 (en) | New 6xxx aluminum alloys, and methods of making the same | |
US5624504A (en) | Duplex structure stainless steel having high strength and elongation and a process for producing the steel | |
EP2009130B1 (en) | Process for producing alloyed hot-dip zinc-coated steel sheet satisfactory in processability, non-powdering property, and sliding property | |
EP1741800A1 (en) | Steel sheet for can and method for production thereof | |
EP1990430B1 (en) | High-strength hot rolled steel plate and manufacturing method thereof | |
EP0672758A1 (en) | Method of manufacturing canning steel sheet with non-aging property and superior workability | |
EP1905848A2 (en) | Cold-rolled steel sheet or hot-rolled steel sheet excellent in painting bake hardenability and anti aging property at room temperature, and method of producing the same | |
CN110959049A (en) | Flat steel product with good aging resistance and method for the production thereof | |
US20150267284A1 (en) | Methods for production of highly formable extra deep draw enameling steel -- product and process for manufacture thereof | |
EP0385257B1 (en) | Method of producing hardened aluminium alloy forming sheet having high strength and superior corrosion resistance | |
EP3186406B1 (en) | Cold rolled high strength low alloy steel strip | |
EP1513961B1 (en) | Steel sheet for vitreous enameling and production method | |
US6316127B1 (en) | Galvanized steel sheet superior in ductility and process for production thereof | |
KR20190077176A (en) | Zinc-based metal plated steel sheet having excellent anti-aging property at room temperature and bake hardenability, and manufacturing method for the same | |
EP3978643A2 (en) | Austenitic stainless steel having improved strength, and method for manufacturing same | |
JPH03277741A (en) | Dual-phase cold roller steel sheet excellent in workability, cold nonaging properties and baking hardenability and its manufacture | |
EP2527481B1 (en) | Quenched steel sheet having excellent hot press formability, and method for manufacturing same | |
EP3683328B1 (en) | Steel sheet having excellent image clarity after coating and method for manufacturing same | |
EP1233079B1 (en) | Cold reduced enamelling steel sheet and an enamelled structure comprising a component of such a steel sheet | |
EP1336665B1 (en) | Cold reduced enamelling steel sheet and an enamelled structure comprising a component of such a steel sheet | |
US20210025046A1 (en) | Automotive outer panel made from a 6xxx-series aluminium alloy sheet product | |
KR102403849B1 (en) | High strength austenitic stainless steel with excellent productivity and cost saving effect, and method for manufacturing the same | |
KR101736634B1 (en) | Cold-rolled steel sheet and galvanized steel sheet having excellent hole expansion and ductility and method for manufacturing thereof | |
EP0432498A2 (en) | High tensile cold rolled steel sheet and high tensile not dip galvanized steel sheet having improved stretch flanging property and process for producing same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
AX | Request for extension of the european patent |
Extension state: AL LT LV MK RO SI |
|
17P | Request for examination filed |
Effective date: 20040220 |
|
AKX | Designation fees paid |
Designated state(s): BE CH FI FR GB LI TR |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: 8566 |
|
17Q | First examination report despatched |
Effective date: 20050919 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): BE CH FI FR GB LI TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20090403 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 15 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 16 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 17 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 20180227 Year of fee payment: 17 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20190219 Year of fee payment: 16 Ref country code: FI Payment date: 20190227 Year of fee payment: 18 |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20190228 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190228 |
|
REG | Reference to a national code |
Ref country code: FI Ref legal event code: MAE |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200218 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200229 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200229 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20210223 Year of fee payment: 20 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: TR Payment date: 20210209 Year of fee payment: 20 Ref country code: GB Payment date: 20210225 Year of fee payment: 20 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: PE20 Expiry date: 20220217 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION Effective date: 20220217 |